Browsing by Author "Kumar, Harsha P."
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Item Browsing Hierarchical Data with Multi-Level Dynamic Queries and Pruning(1995) Kumar, Harsha P.; Plaisant, C.; Shneiderman, B.; ISR; CSHCNUser often must browse hierarchies with thousands of nodes in search of those that best match their information needs. The PDQ Tree-browser (Pruning with Dynamic Queries) visualization tool was specified, designed and developed for this purpose. This tool presents trees in two tightly-coupled views, one a detailed view and the other an overview. Users can use dynamic queries, a method for rapidly filtering data, to filter nodes at each level of the tree. The dynamic query panels are user-customizable. Subtrees of unselected nodes are pruned out, leading to compact views of relevant nodes. Usability testing of the PDQ Tree- browser, done with 8 subjects, helped asses strengths and identify possible improvement. The PDQ Tree-browser was used in Network Management (600 nodes) and University Finder (1100 nodes) applications. A controlled experiment, with 24 subjects, showed that pruning significantly improved performance speed and subjective user satisfaction. Future research directions are suggested.Item Browsing Hierarchical Data with Multi-Level Dynamic Queries and Pruning(1995) Kumar, Harsha P.; Shneiderman, B.; ISR; CSHCNUsers often must browse hierarchies with thousands of nodes in search of those that best match their information needs. The tree-browser visualization tool was specified, designed and developed for this purpose. This tool presents trees in two tightly-coupled views, one a detailed view and the other an overview. Users can use dynamic queries, a method for rapidly filtering data, to filter nodes at each level of the tree. The dynamic query panels are user-customizable. Subtrees of unselected nodes are pruned out, leading to compact views of relevant nodes.The software architecture, data structures and algorithms used to achieve this behavior are specified. Usability testing of the Tree-browser, done with 8 subjects, helped assess strengths and identify possible improvements. The Tree-browser was applied to the Network Management (600 nodes) and UniversityFinder (1100 nodes) application. Future research directions are suggested.
Item Next Generation Network Management Technology(1994) Atallah, George C.; Ball, Michael O.; Baras, John S.; Goli, Shravan K.; Karne, Ramesh K.; Kelley, Stephen; Kumar, Harsha P.; Plaisant, Catherine; Roussopoulos, Nick; Shneiderman, Ben; Srinivasarao, Mulugu; Stathatos, Kostas; Teittinen, Marko; Whitefield, David; ISR; CSHCNToday's telecommunications networks are becoming increasingly large, complex, mission critical and heterogeneous in several dimensions. For example, the underlying physical transmission facilities of a given network may be ﲭixed media (copper, fiber- optic, radio, and satellite); the sub networks may be acquired from different vendors due to economic, performance, or general availability reasons; the information being transmitted over the network may be ﲭultimedia (video, data, voice, and images) and, finally, varying performance criteria may be imposed e.g. data transfer may require high throughput while the others, whose concern is voice communications, may require low call blocking probability. For these reasons, future telecommunications networks are expected to be highly complex in their services and operations. Due to this growing complexity and the disparity among management systems for individual sub networks, efficient network management systems have become critical to the current and future success of telecommunications companies. This paper addresses a research and development effort which focuses on prototyping configuration management, since that is the central process of network management and all other network management functions must be built upon it. Our prototype incorporates ergonomically designed graphical user interfaces tailored to the network configuration management subsystem and to the proposed advanced object-oriented database structure. The resulting design concept follows open standards such as Open Systems Interconnection (OSI) and incorporates object oriented programming methodology to associate data with functions, permit customization, and provide an open architecture environment.- A revised version of this technical report has been published in
The 12th Symposium on Space Nuclear Power and Propulsion/Commercialization, pp. 75-82, Albuquerque, NM, January 8-12, 1995.Item Using Interaction Object Graphs to Specify and Develop Graphical Widgets(1994) Carr, David A.; Jog, Ninog; Kumar, Harsha P.; Teittinen, Marko; Ahlberg, Christopher; ISRThis document describes five widgets that have been developed at the Human-Computer Interaction Laboratory of the University of Maryland. These widgets are: a range selection slider, a two- level alpha-slider, a secure switch, a tree viewer, and a treemap viewer. The last two use the same tree representation and can be used as alternate visualizations of the same hierarchy. In addition, a system for widget specification is introduced and each widget is specified using this system.Item Visual Information Management for Network Configuration(1994) Kumar, Harsha P.; Plaisant, C.; Teittinen, M.; Shneiderman, B.; ISR; CSHCNCurrent network management systems rely heavily on forms in their user interfaces. The interfaces reflect the intricacies of the network hardware components but provide little support for guiding users through tasks. There is a scarcity of useful graphical visualizations and decision-support tools. We applied a task-oriented approach to design and implemented the user interface for a prototype network configuration management system. Our user interface provides multiple overviews of the network (with potentially thousands of nodes) and the relevant configuration tasks (queries and updates). We propose a unified interface for exploration, querying, data entry and verification. Compact color-coded treemaps with dynamic queries allowing user- controlled filtering and animation of the data display proved well-suited for representing the multiple containment hierarchies in networks. Our Tree-browser applied the conventional node-link visualization of trees to show hardware containment hierarchies. Improvements to conventional scrollbar-browsers included tightly coupled overviews and detailed views. This visual interface, implemented with Galaxy and the University of Maryland Widget Library TM, has received enthusiastic feedback from the network management community. This application-specific paper has design paradigms that should be useful to designers of varied systems.